//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2012 EMC Corp.
//
//	@filename:
//		IMDRelStats.h
//
//	@doc:
//		Interface for relation stats
//---------------------------------------------------------------------------



#ifndef GPMD_IMDRelStats_H
#define GPMD_IMDRelStats_H

#include "gpos/base.h"
#include "gpos/common/CDouble.h"

#include "naucrates/md/IMDCacheObject.h"

namespace gpmd
{
	using namespace gpos;
	using namespace gpdxl;

	//---------------------------------------------------------------------------
	//	@class:
	//		IMDRelStats
	//
	//	@doc:
	//		Interface for relation stats
	//
	//---------------------------------------------------------------------------
	class IMDRelStats : public IMDCacheObject
	{		
		public:
		
			// object type
			virtual
			Emdtype MDType() const
			{
				return EmdtRelStats;
			}
		
			// number of rows
			virtual
			CDouble Rows() const = 0;			

			// is statistics on an empty input
			virtual
			BOOL IsEmpty() const = 0;
	};
}

#endif // !GPMD_IMDRelStats_H

// EOF
